Deconstructing Datalog

The author describes their PhD dissertation on "Datafun," a new language that integrates Datalog's logic programming features—particularly recursive queries—into a typed functional programming language by reformulating predicates as set operations and adding a least fixed-point operator. The dissertation demonstrates that this combination is both theoretically sound and practically implementable, with the key innovation being a type system that tracks monotonicity to capture Datalog's stratification condition for ensuring well-defined recursive queries.